It is known that a detecting device detects microvibration (biosignal) such as heartbeat and/or respiration of a human body that is supported by a supporting member such as a bed, a mattress or a seat. A detecting device having a plurality of sensor elements (detecting portions) at a supporting member for detecting microvibration is disclosed in JP2006258693A (paragraphs 26-30, and FIG. 8). The plurality of sensor elements are sequentially checked one by one in order to measure the microvibration within an area where the plurality of the sensor elements are provided. According to the detecting device disclosed in JP2006258693A, a large number of sensor elements are provided within a target area for detecting the microvibration. Therefore, measurement of the microbivration with higher resolution is achieved.
The detecting device disclosed in JP2006258693A measures the microbivration within the target area, therefore, the biosignal is detected without being largely influenced by a posture of the human body on the supporting member. However, it is not necessary to measure an entire target area for detecting the biosignal. In other words, some of the plurality of the sensor elements provided within the target area may not be necessary. Providing sensor elements that may not necessary for detecting the biosignal at the supporting member may increase manufacturing costs. However, the sensor elements that are necessarily arranged at the supporting member vary depending on to which supporting member the sensor elements are provided. Therefore, positioning of the sensor elements may not easily be determined.
A need thus exists for a biosignal intensity distribution measuring apparatus which is not susceptible to the drawback mentioned above.